非共价相互作用对中心手性的影响及中心手性的定义

建立在van't Hoff碳正四面体构型学说基础上的中心手性的概念未涉及非共价相互作用对分子中心手性的影响.可以想像,当某原子连有两个相同的原子或基团(如氢原子)时,可因非共价相互作用(如分子内氢键)的存在(如只与其中的一个氢原子形成氢键)成为不等性原子或基团.考虑到非共价相互作用对分子中心手性可能产生的影响,中心手性的概念似应为:一个原子(如C,N)的四支键分别指向四面体的各顶点,并分别键连四个不等性原子或基团(包括孤电子对)时,则该原子是手性的.

The noncovalent interaction induce central chirality and the difination for central chirality

The concept central chirality, which is founded on the van't Hoff's hypothesis of tetrahedral configuration of carbon atom, has been widely used until now. However, some consideration may conflict with this concept because the relationship between noncovalent interactions and central chirality seems neglected. It is proposed a new concept on central chirality "any molecule containing an atom that has four bonds pointing to the corners of a tetrahedron (or pyramid) will be chiral if the four groups/atoms (including unshared pair of electrons) are unequal". This concept emphasizes the word "unequal" because it has the meaning of poorly balanced or matched in quantity or value or measure. Obviously, this concept has the least restriction to the groups/atoms or unshared pair of electrons involved since the contribution of hydrogen bond (or other noncovalent interactions) to central chirality will be included.